We are examing the proteins transported intra-axonally in the retino-collicular and retino-geniculate pathways at fast and intermediate rates. These proteins are labeled by injecting 35S-methionine in the vicinity of the retina. The labeled optic tract (ON), lateral geniculate nucleus (LGN) and superior colliculus (SC) are homogenized and the proteins analyzed by two-dimensional gel electrophoresis, in which isoelectric focussing procedes electrophoresis in SDS. Using Dutch-belted rabbits, we can reproducibly identify about 150 transported proteins in these three region and about 14 which are labeled non-specifically by blood borne radioactivity. The protein pattern depends on the age of the animal, the transport time and the distance transported. The only reproducible difference was found between the LGN and SC, involved a charge difference in a major protein. We are studying proteins transported to these nuclei from the cortex, changes induced by visual deprivation and developmental changes.